Back in the early days of the fandom, particularly aroun the 2011-2012 era, Hasbro was pretty damn excited that their pony brand was becoming essentially a massive internet meme. Internally, they apparently analysed the hell out of us with a very interesting book called "Pop Goes the Pony!" dedicated to all things brony fandom. It was apparently used to get people up to speed on what we are all about.
It delves into everything, from us here at Equestria Daily, to fandom favorite characters, as well as a huge section all about humanized pony fanart that probably spawned the Equestria Girls show. They use fan art from WAY back the, collection on both 4chan and Equestria Daily. We are mentionled alot in fact!
Apparently a comic book shop right down by Hasbro HQ ended up with this guide to all things mlp fandom, and someone there scanned it all for the internet. It has started making the rounds via a PDF. Usually we don't post MEGA links, but considering Hasbro apparently sold this thing off, it seems like they don't mind it being shared now.
Anyway, go check it out over here if you are curious!